Qlik Sense Mobile: Websocket connection is getting blocked by Citrix Netscaler, Azure Web Application Firewall, Etc.

[Damien_V]

When using the Qlik Sense Mobile app for iOS or Android behind Citrix Netscaler, Azure Web Application Firewall, Etc no app can be opened, while it works fine from a browser on the same device.

Environments:

Qlik Sense Enterprise on Windows February 2019 and later

Qlik Sense Mobile February 2019 and later

Resolution:

When opening the websocket connection in the Qlik Sense mobile native app, the websocket connection is established by native code using the Host header, the value of the Host header will include the Qlik Sense server name and port (example: qliksenseservername:443)

There is a default policy in Netscaler that is blocking the use of port number in the host header, this policy will need to be modified in order for Qlik Sense mobile to be able to establish the websocket connection.

With respect to Azure Web Application Firewall, ask Azure team to investigate the issue and allow the required ports and Host headers.

In order to confirm that this is the issue, a simple test would be to install an extension to modify headers in your browser (such as Modheaders) and modify the Host header to yourservername:443, then see if you can open a Qlik Sense app from the hub when going through Netscaler or Azure Web Application Firewall.

Netscaler will usually return error code 503 if the policy blocking the header is active and Azure Web Application Firewall will return error code 403, Forbidden